Hi Doug, 

That makes total sense! Thanks so much for looking into this. 

Best, 
Suzanne


On Tue, Oct 29, 2013 at 3:57 PM, Douglas N Greve <greve@nmr.mgh.harvard.edu> wrote:

For condition 4 (posslope), the weight is always 0. You can't compute a slope if all the values are the same.
doug



On 10/29/2013 10:44 AM, Suzanne Oosterwijk wrote:
Hi Doug,

Attached is the Xtmp.mat file for the analysis that gets the error.

Thanks for your response on the second question. I am not sure what you mean with demeaning, so I guess that I am not doing that :-) I just wanted to make sure that not getting the same results does not indicate a fundamental problem in my paradigm files.

Thanks!
Suzanne


On Tue, Oct 29, 2013 at 3:31 PM, Douglas N Greve <greve@nmr.mgh.harvard.edu <mailto:greve@nmr.mgh.harvard.edu>> wrote:

    Hi Suzanne, can you send me the Xtmp.mat file that gets created?

    On your second question, the answer might be a little tricky.
    First, are you demeaning the modulation value? If not, then you
    can certainly get different maps. The other part is that you can
    get unpredicatable results because the design matrix is not
    orthogonalbecause you have several event types.

    doug



    On 10/28/2013 12:30 PM, Suzanne Oosterwijk wrote:

        Hi Doug,

        I am running parametric modulation analyses in which I am
        modeling 5 different ratings given by participants in response
        to images. To model these ratings I made paradigm files
        defining both the onset and the slope for each trial (see
        email exchange below). Since I have 5 different ratings, I
        made 5 different paradigm files per participant, per run.
        These paradigm files hold the exact same trial sequence, only
        with different numbers for the slope condition. When running
        selxavg3-sess I get the following error:

        Input to SVD must not contain NaN or Inf.

        Error in cond (line 36)
        s = svd(A);

        Error in fast_selxavg3 (line 279)
        XCond = cond(XtX);

        The strange thing is that selxavg3-sess stops running at a
        particular participant when I am trying to model one
        particular rating, whereas the exact same analysis for the
        other three ratings I have run so far (for the same
        participant) does not result in an error. I checked the
        paradigm files over and over but I cannot find the mistake.
        The paradigm files are all the same in terms of timing and
        condition codes etc., the only thing that is different between
        the files are the specific ratings per trial. So I really
        don't understand why I get this error. I attached the paradigm
        files for the erroneous analysis and also for the analysis
        that runs successfully. I also attached the selxavg3-sess
        logfile for the an erroneous analysis and for the successful
        one. Maybe I am missing something here, but I just don't see it.

        Also, I have one other question concerning the parametric
        modulation. As I understand it modeling the onset is the same
        analysis as a normal contrast comparing a particular condition
        against baseline. I compared the onset significance maps
        (comparing onset to baseline) for each separate rating, and to
        my surprise they are not the same. Since only the ratings
        differ between the different analyses, and not the onset times
        of the stimuli, I expected those maps to be completely
        identical. Am I right in this assumption, or is there a reason
        they can be different?

        Thanks!
        Suzanne



        On Thu, Aug 15, 2013 at 4:28 PM, Douglas Greve
        <greve@nmr.mgh.harvard.edu <mailto:greve@nmr.mgh.harvard.edu>
        <mailto:greve@nmr.mgh.harvard.edu

        <mailto:greve@nmr.mgh.harvard.edu>>> wrote:

            Hi Suzanne, that is fine
            doug



            On 8/14/13 7:13 AM, Suzanne Oosterwijk wrote:

                Hi Doug,

                Just a follow-up question. The ratings that I
            collected for the
                parametric modulation analysis have a range from 0 to
            1. This
                means that the weights for some stimuli will have the
            value 0. Is
                this a problem? I am asking just to make sure that a
            weight of 0
                does not exclude the corresponding data-point.

                Thanks,
                Suzanne


                On Fri, Jul 26, 2013 at 7:14 PM, Douglas Greve
                <greve@nmr.mgh.harvard.edu
            <mailto:greve@nmr.mgh.harvard.edu>
            <mailto:greve@nmr.mgh.harvard.edu

            <mailto:greve@nmr.mgh.harvard.edu>>> wrote:

                    Hi Suzanne, yes that looks correct.
                    doug



                    On 7/26/13 9:27 AM, Suzanne Oosterwijk wrote:

                        Hello all,

                        I want to perform a parametric modulation
                analysis in
                        Freesurfer and I have a question about how to
                adapt my
                        paradigm file. I understand how to code the
                offset and the
                        slope (by adding the individual ratings as the
                slope
                        weight), but I just want to check whether I am
                correctly
                        modelling the trials of no interest.

                        I have presented people with negative,
                positive and neutral
                        images all preceded by a fixation cross. I
                have individual
                        ratings for the negative images that I want to
                use for the
                        parametric modulation analysis, but I don't
                have any ratings
                        for the positive and neutral images. I do want
                to model
                        these images and the fixation cross, however,
                to make sure
                        that do not become part of the null. Based on
                the wiki I
                        adapted my paradigm file like this:

                        (1 = offset for the negative image; 2 = slope
                for the
                        negative image; 3 = neu/pos image of no
                interest; 4 = fixation)

                        00121NULL
                        12431fix
                        15131negoffset
                        1523.79negslope
                        18431fix
                        21331neu/pos
                        24431fix
                        27131negoffset
                        27231.00negslope
                        30431fix
                        33131negoffset
                        3323.49negslope
                        36091NULL
                        etc.

                        Is this correct?

                        Thanks so much for responding!
                        Suzanne



                        --
                        Suzanne Oosterwijk, Ph.D.

                        Postdoctoral Researcher

                        Department of Social Psychology

                        University of Amsterdam

                        s.oosterwijk@u <mailto:s.oosterwijk@neu.edu
                <mailto:s.oosterwijk@neu.edu>>va.nl <http://va.nl>
                <http://va.nl>


                https://sites.google.com/site/suzanneoosterwijk/

                        __._,_.___
                        Reply via web post
                                       <http://groups.yahoo.com/group/martinos-tech/post;_ylc=X3oDMTJwM2ltbGk0BF9TAzk3MzU5NzE0BGdycElkAzQ5ODAyNjAEZ3Jwc3BJZAMxNzA1NzI4NjExBG1zZ0lkAzU4MzAEc2VjA2Z0cgRzbGsDcnBseQRzdGltZQMxMzc0ODQ1MjUy?act=reply&messageNum=5830>
                                Reply to sender
                        <mailto:suzanne.oosterwijk@gmail.com
                <mailto:suzanne.oosterwijk@gmail.com>?subject=Re%3A%20parametric%20modulation>
                                Reply to group
                        <mailto:martinos-tech@yahoogroups.com
                <mailto:martinos-tech@yahoogroups.com>?subject=Re%3A%20parametric%20modulation>
                                Start a New Topic
                                       <http://groups.yahoo.com/group/martinos-tech/post;_ylc=X3oDMTJlMGwxMWZ1BF9TAzk3MzU5NzE0BGdycElkAzQ5ODAyNjAEZ3Jwc3BJZAMxNzA1NzI4NjExBHNlYwNmdHIEc2xrA250cGMEc3RpbWUDMTM3NDg0NTI1Mg-->
                                Messages in this topic
                                       <http://groups.yahoo.com/group/martinos-tech/message/5830;_ylc=X3oDMTM0bWtjcmt0BF9TAzk3MzU5NzE0BGdycElkAzQ5ODAyNjAEZ3Jwc3BJZAMxNzA1NzI4NjExBG1zZ0lkAzU4MzAEc2VjA2Z0cgRzbGsDdnRwYwRzdGltZQMxMzc0ODQ1MjUyBHRwY0lkAzU4MzA->


                        (1)

                        Recent Activity:

                        Visit Your Group
                                       <http://groups.yahoo.com/group/martinos-tech;_ylc=X3oDMTJlNWFnMGY0BF9TAzk3MzU5NzE0BGdycElkAzQ5ODAyNjAEZ3Jwc3BJZAMxNzA1NzI4NjExBHNlYwN2dGwEc2xrA3ZnaHAEc3RpbWUDMTM3NDg0NTI1Mg-->

                        Yahoo! Groups
                                       <http://groups.yahoo.com/;_ylc=X3oDMTJkNzk1aW9nBF9TAzk3NDc2NTkwBGdycElkAzQ5ODAyNjAEZ3Jwc3BJZAMxNzA1NzI4NjExBHNlYwNmdHIEc2xrA2dmcARzdGltZQMxMzc0ODQ1MjUy>

                        Switch to: Text-Only
                                       <mailto:martinos-tech-traditional@yahoogroups.com
                <mailto:martinos-tech-traditional@yahoogroups.com>?subject=Change%20Delivery%20Format:%20Traditional>,
                        Daily Digest

                        <mailto:martinos-tech-digest@yahoogroups.com
                <mailto:martinos-tech-digest@yahoogroups.com>?subject=Email%20Delivery:%20Digest>
                        • Unsubscribe
                                       <mailto:martinos-tech-unsubscribe@yahoogroups.com
                <mailto:martinos-tech-unsubscribe@yahoogroups.com>?subject=Unsubscribe>
                        • Terms of Use
                <http://docs.yahoo.com/info/terms/> • Send us
                        Feedback
                        <mailto:ygroupsnotifications@yahoogroups.com
                <mailto:ygroupsnotifications@yahoogroups.com>?subject=Feedback%20on%20the%20redesigned%20individual%20mail%20v1>

                        .

                        __,_._,___


                    The information in this e-mail is intended only
            for the
                    person to whom it is
                    addressed. If you believe this e-mail was sent to
            you in
                    error and the e-mail
                    contains patient information, please contact the
            Partners
                    Compliance HelpLine at
            http://www.partners.org/complianceline . If the e-mail was
                    sent to you in error
                    but does not contain patient information, please
            contact the
                    sender and properly
                    dispose of the e-mail.




                --
                Suzanne Oosterwijk, Ph.D.

                Postdoctoral Researcher

                Department of Social Psychology

                University of Amsterdam

                s.oosterwijk@u <mailto:s.oosterwijk@neu.edu
            <mailto:s.oosterwijk@neu.edu>>va.nl <http://va.nl>
            <http://va.nl>

            https://sites.google.com/site/suzanneoosterwijk/





        --
        Suzanne Oosterwijk, Ph.D.

        Postdoctoral Researcher

        Department of Social Psychology

        University of Amsterdam

        s.oosterwijk@u <mailto:s.oosterwijk@neu.edu
        <mailto:s.oosterwijk@neu.edu>>va.nl <http://va.nl> <http://va.nl>


        https://sites.google.com/site/suzanneoosterwijk/


    --     Douglas N. Greve, Ph.D.
    MGH-NMR Center
    Outgoing:
    ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/




--

Suzanne Oosterwijk, Ph.D.

Postdoctoral Researcher

Department of Social Psychology

University of Amsterdam

s.oosterwijk@u <mailto:s.oosterwijk@neu.edu>va.nl <http://va.nl>

https://sites.google.com/site/suzanneoosterwijk/




--

Suzanne Oosterwijk, Ph.D.

Postdoctoral Researcher

Department of Social Psychology

University of Amsterdam

s.oosterwijk@uva.nl

 

https://sites.google.com/site/suzanneoosterwijk/